Answer:
Two key steps in the method of determining if the genome is circular are:
Agarose Gel Electrophoresis: Perform agarose gel electrophoresis to separate the DNA fragments based on their size. In the case of a circular genome, when the DNA is digested with restriction enzymes, the resulting fragments will exhibit a characteristic circular pattern on the gel, with no distinct linear fragments.
Plasmid Extraction and Restriction Enzyme Digestion: Isolate the DNA, specifically plasmid DNA if applicable, and perform restriction enzyme digestion. Restriction enzymes specifically recognize and cleave DNA at specific sequences. If the genome is circular, the restriction enzyme digestion will produce fragments that appear as a ladder-like pattern on agarose gel electrophoresis, with the highest molecular weight band being the full circular genome itself.